In adults, blocked tear ducts, which cause tears to build up in the eyes, may be caused by one or more conditions. They include:
Thickening of the tear duct lining. The tear ducts may become narrow due to thickening, swelling, or inflammation of their lining. This is called primary acquired nasolacrimal duct obstruction (PANDO) and is most common in women over the age of 40.
Nasal problems, such as:
An abnormal growth of tissue in the nose (nasal polyps), or tumors.
Excessive growth of nasal bones.
Misshapen bone (deviated septum) and/or cartilage (rubbery tissue that coats the ends of bones) that divides the nostrils.